This invention relates generally to a machine for moving quantities of product or items, into, through and out of a controlled environment in a continuous process. The length of the process or retention time within the controlled environment, to be determined in part by the length of the conveyor and the length of the conveyor is determined by, the size and how often it traverses, the controlled environment. A partial list of these environments might include: A freezer for food processing, a low temperature oven for bread proofing, a medium temperature oven for bread baking or a high temperature oven for annealing or heat treating.